Internal combustion engines are often used to power inboard or outboard motors for propelling watercraft. These engines are operated in environments which expose them to conditions favoring corrosion. For example, the watercraft may be operated in a body of salt water, with the engine exposed to both the liquid water and salt air.
Corrosion may damage a variety of sensitive parts of the engine, such as the fuel injectors, high pressure fuel rail and related componentry. As such, it has been found desirable to deliver lubricant to these components to minimize the corrosive effects.
Several problems are encountered in providing lubricant to the functions. Preferably, an oil level sensor 78 is provided corresponding to the main lubricant tank 58. This sensor 78 provides data to the ECU 76 regarding the level of lubricant in the tank 58. A similar sensor 80 is preferably provided corresponding to the secondary lubricant tank 62.
As is well known in the art of engine control, the ECU 76 utilizes the sensor data to optimize engine operating parameters. For example, the ECU 76 utilizes the data to change the ignition coil(s) and selectively fire the ignition element corresponding to each cylinder lubricant or "oil" supply system provides oil into the fuel being supplied to the engine for mixing therewith, so that a mixture of oil and fuel is supplied to each charge former.
In accordance with the present invention, a fluid pressure activated check valve is positioned along the lubricant supply system before a point of introduction of the lubricant into the fuel, whereby fuel is prevented from flowing into the lubricant supply system. Preferably, the check valve includes fluid sensor means for sensing the fluid and providing data to a control unit. The sensor means may comprise a fluid pressure or flow rate sensor. The control unit is arranged to utilize data from the sensor to control the delivery of lubricant into the fuel system.
Further objects, features, and advantages of the present invention over the prior art will become apparent from the detailed description of the drawings which follows, when considered with the attached figures.